Sunday, July 30, 2006

Those wacky microeconomists are looking in places where the average Joe would be surprised to find an economist (no, most of us have no expertise in stocks, bond and foreign exchange). So reports the New York Times.

New research from around the world has begun to reveal a picture of humans today that is so different from what it was in the past that scientists say they are startled. Over the past 100 years, says one researcher, Robert W. Fogel of the University of Chicago, humans in the industrialized world have undergone “a form of evolution that is unique not only to humankind, but unique among the 7,000 or so generations of humans who have ever inhabited the earth.”

The difference does not involve changes in genes, as far as is known, but changes in the human form. It shows up in several ways, from those that are well known and almost taken for granted, like greater heights and longer lives, to ones that are emerging only from comparisons of health records.

The biggest surprise emerging from the new studies is that many chronic ailments like heart disease, lung disease and arthritis are occurring an average of 10 to 25 years later than they used to. There is also less disability among older people today, according to a federal study that directly measures it. And that is not just because medical treatments like cataract surgery keep people functioning. Human bodies are simply not breaking down the way they did before.. . .Dr. Barker of Oregon Health and Science University is intrigued by the puzzle of who gets what illness, and when. “Why do some people get heart disease and strokes and others don’t?” he said. “It’s very clear that current ideas about adult lifestyles go only a small way toward explaining this. You can say that it’s genes if you want to cease thinking about it. Or you can say, When do people become vulnerable during development? Once you have that thought, it opens up a whole new world.”

It is a world that obsesses Dr. Barker. Animal studies and data that he and others have been gathering have convinced him that health in middle age can be determined in fetal life and in the first two years after birth.. . .But not everyone was convinced by what has come to be known as the Barker hypothesis, the idea that events very early in life affect health and well-being in middle and old age. One who looked askance was Douglas V. Almond, an economist at Columbia University.

Dr. Almond had a problem with the studies. They were not of randomly selected populations, he said, making it hard to know if other factors had contributed to the health effects. He wanted to see a rigorous test — a sickness or a deprivation that affected everyone, rich and poor, educated and not, and then went away. Then he realized there had been such an event: the 1918 flu.

The flu pandemic arrived in the United States in October 1918 and was gone by January 1919, afflicting a third of the pregnant women in the United States. What happened to their children? Dr. Almond asked.

He compared two populations: those whose mothers were pregnant during the flu epidemic and those whose mothers were pregnant shortly before or shortly after the epidemic.

To his astonishment, Dr. Almond found that the children of women who were pregnant during the influenza epidemic had more illness, especially diabetes, for which the incidence was 20 percent higher by age 61. They also got less education — they were 15 percent less likely to graduate from high school. The men’s incomes were 5 percent to 7 percent lower, and the families were more likely to receive public assistance.

The effects, Dr. Almond said, occurred in whites and nonwhites, in rich and poor, in men and women. He convinced himself, he said, that there was something to the Barker hypothesis.

If life in the womb and in the first two years has such a large impact, that bodes well for Jeffrey Sach's program of concentrating development aid on direct relief of extreme poverty: people will be able to lead much more productive lives. And, no, I have not lost track of the opposite direction of causality that Fogle points to: the Industrial revolution has allowed people to live longer with fewer disabilities.

Economic development even seems to be a cure for cancer:

“Suppose you were a survivor of typhoid or tuberculosis,” Dr. Fogel said. “What would that do to aging?” It turned out, he said, that the number of chronic illnesses at age 50 was much higher in that group. “Something is being undermined,” he said. “Even the cancer rates were higher. Ye gods. We never would have suspected that.”

Life for UAE nationals was quite harsh up until 40 or 50 years ago. The first two years of life for someone born here in 1960 was quite different for someone born here in 1980. Yes, we are seeing lots of childhood obesity. But is that extra weight due to a good start in life or to an unhealthy lifestyle? Moreover, even if it is the latter going back to the economy of the 1960s would be literally unhealthy.

1 Comments:

Highly interesting. I wasn't aware of the Barker Hypothesis before, but have just been reading about 'thrifty phenotypes." Much is still unproven when it comes to the hypothesis, but perhaps this does explain obesity in the national population?

If conditions during pregnancy are bad, the foetus is programmed to survive in an environment where resources are perenially short-smaller size, lower metabolism, what have you. And when a thrifty phenotype is exposed to an affluent lifestyle, you run the risk of overloading their sparse-resource oriented systems, leading to obesity, diabete4s, etc.